1. Technical Field
This invention relates generally to conveyor systems, and more particularly to grit removal conveyor systems for use in a corrosive environment.
2. Discussion of The Related Art
In addition to water, waste water typically contains waste solids commonly referred to as grit (i.e., non-biodegradable solids such as stones, sand, or glass), sludge, and scum all requiring separation from the water prior to final treatment. Waste water treatment systems commonly involve multiple filtering stages, of which grit removal is of the utmost importance. Because of the abrasive properties of grit, effective and efficient grit removal during the early treatment stages minimizes wear on a system's subsequent waste water treatment devices. Grit removal systems utilizing settling tanks are well known.
Currently, grit removal systems displaced within a settling tank use steel components to drag, without physically lifting, settled grit along the tank's bottom surface to a disposal means. Unfortunately, the prior art system's steel components have high susceptibility to accelerated corrosion from exposure to air and waste water treatment chemicals during operation and maintenance procedures. In addition, a steel grit removal system is heavy and prone to excessive wear when supporting and dragging the steel components within the system's settling tank. This combination of factors reduces a prior art system's efficiency and durability and increases maintenance costs.
Thus, it would be desirable to produce a grit removal system with reduced weight for increased efficiency and durability and with high immunity to corrosion from exposure to natural elements and chemicals. Further, it would be desirable to provide a technique for removing grit from a settling tank by directly lifting the collected grit from the waste water to a disposal means.